This invention relates to an image display system. More particularly, the invention relates to an image display panel or screen which is automatically actuated to display different or varying images of all kind of visible information like portraits, objects, scenes, alphanumeric information in a long or short lasting manner. The invention further relates to an image display process.
Devices for displaying different images are known in the art. Thus, U.S. Pat. No. 3,273,140 discloses a display panel equipped with a multitude of lamps which are partially lighted according to a program so that an image can be formed by the combination of illuminated and dark lamps. Furthermore, a similar device has been known from U.S. Pat. No. 2,239,522 where color lamps are used, and from U.S. Pat. No. 3,210,757. Another kind of display panel has been proposed in U.S. Pat. No. 3,270,447. In this patent, the display screen is divided into a multitude of cells wherein a reflector is provided in each such cell, the reflectors being able to be moved at different depths in their respective cells by means of solenoids having multiple windings.
From U.S. Pat. No. 3,486,258, a display means for displaying moving pictures is known wherein display elements are mechanically transported behind a panel.
In U.S. Pat. No. 3,482,344 a display panel is described wherein flat display members, rotable about 180.degree., are provided; to set and reset an image, the whole panel must be moved from one station to another where the members are moved by fluid motions.
These known devices suffer from the serious disadvantage that their electrical energy requirements are tremendously high; furthermore, they are quite expensive to manufacture, and in display panels using electric lamps, maintenance problems are severe since lamps must often be replaced, and replacement is not easy. The lighted spots in lamp display panels further do not cover the entire surface of the panel since the lamps have a circular front area.
Other known display devices are by far too expensive or too complicated for practical use.
An effective and rapidly working dot image display system and process has been disclosed by us in in the copending U.S. patent application Ser. No. 942,972, now U.S. Pat. No. 4,186,394, the contents of which has not yet been published anywhere. This application is incorporated by reference into the present application.
It is therefore an object of the present invention to provide a novel display panel or screen which is automatically actuated to selectively exhibit different visible information like images of persons, scenes, signs, advertisements, etc.
It is a second object of the invention to provide a display system which is perfectly visible in normally or artificially lighted rooms like halls, airport lounges, etc., and which can also be used as a daytime outside display.
It is a further, important object of the invention to provide a display system capable of showing images comprising the so-called half tone reproduction.
It is another object of the invention to provide a display system similar to a dot matrix where the individual dots cannot be distinguished by the naked human eye, the displayed image thus appearing as a continuous dot-free pattern.
Still a further object of this invention is a display panel composed of modules, each module comprising a plurality of elements which are each composed of display sub-elements, thus speeding up the image setting and resetting operations.
A still further object of the invention is to provide such modules, elements and sub-elements which are very simple and inexpensive but are working with perfect reliability.
It is another object of the invention to provide a process for displaying images wherein, when a particular and predetermined image has been displaced, the next one can be displayed by resetting said image and setting a new one simultaneously with the read-out of data from a data carrier so that no pre-setting of a new image is necessary, thus speeding up the sequence of images to be displayed in intervals.